The current netlink API for WireGuard does not directly support removal
of allowed ips from a peer. A user can remove an allowed ip from a peer
in one of two ways:
1. By using the WGPEER_F_REPLACE_ALLOWEDIPS flag and providing a new
list of allowed ips which omits the allowed ip that is to be removed.
2. By reassigning an allowed ip to a "dummy" peer then removing that
peer with WGPEER_F_REMOVE_ME.
With the first approach, the driver completely rebuilds the allowed ip
list for a peer. If my current configuration is such that a peer has
allowed ips 192.168.0.2 and 192.168.0.3 and I want to remove 192.168.0.2
the actual transition looks like this.
[192.168.0.2, 192.168.0.3] <-- Initial state
[] <-- Step 1: Allowed ips removed for peer
[192.168.0.3] <-- Step 2: Allowed ips added back for peer
This is true even if the allowed ip list is small and the update does
not need to be batched into multiple WG_CMD_SET_DEVICE requests, as the
removal and subsequent addition of ips is non-atomic within a single
request. Consequently, wg_allowedips_lookup_dst and
wg_allowedips_lookup_src may return NULL while reconfiguring a peer even
for packets bound for ips a user did not intend to remove leading to
unintended interruptions in connectivity. This presents in userspace as
failed calls to sendto and sendmsg for UDP sockets. In my case, I ran
netperf while repeatedly reconfiguring the allowed ips for a peer with
wg.
/usr/local/bin/netperf -H 10.102.73.72 -l 10m -t UDP_STREAM -- -R 1 -m 1024
send_data: data send error: No route to host (errno 113)
netperf: send_omni: send_data failed: No route to host
While this may not be of particular concern for environments where peers
and allowed ips are mostly static, systems like Cilium manage peers and
allowed ips in a dynamic environment where peers (i.e. Kubernetes nodes)
and allowed ips (i.e. pods running on those nodes) can frequently
change making WGPEER_F_REPLACE_ALLOWEDIPS problematic.
The second approach avoids any possible connectivity interruptions
but is hacky and less direct, requiring the creation of a temporary
peer just to dispose of an allowed ip.
Introduce a new flag called WGALLOWEDIP_F_REMOVE_ME which in the same
way that WGPEER_F_REMOVE_ME allows a user to remove a single peer from
a WireGuard device's configuration allows a user to remove an ip from a
peer's set of allowed ips. This enables incremental updates to a
device's configuration without any connectivity blips or messy
workarounds.
A corresponding patch for wg extends the existing `wg set` interface to
leverage this feature.
$ wg set wg0 peer <PUBKEY> allowed-ips +192.168.88.0/24,-192.168.0.1/32
When '+' or '-' is prepended to any ip in the list, wg clears
WGPEER_F_REPLACE_ALLOWEDIPS and sets the WGALLOWEDIP_F_REMOVE_ME flag on
any ip prefixed with '-'.
Signed-off-by: Jordan Rife <jordan@jrife.io>
[Jason: minor style nits, fixes to selftest, bump of wireguard-tools version]
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Link: https://patch.msgid.link/20250521212707.1767879-5-Jason@zx2c4.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
return 0;
}
+static void remove_node(struct allowedips_node *node, struct mutex *lock)
+{
+ struct allowedips_node *child, **parent_bit, *parent;
+ bool free_parent;
+
+ list_del_init(&node->peer_list);
+ RCU_INIT_POINTER(node->peer, NULL);
+ if (node->bit[0] && node->bit[1])
+ return;
+ child = rcu_dereference_protected(node->bit[!rcu_access_pointer(node->bit[0])],
+ lockdep_is_held(lock));
+ if (child)
+ child->parent_bit_packed = node->parent_bit_packed;
+ parent_bit = (struct allowedips_node **)(node->parent_bit_packed & ~3UL);
+ *parent_bit = child;
+ parent = (void *)parent_bit -
+ offsetof(struct allowedips_node, bit[node->parent_bit_packed & 1]);
+ free_parent = !rcu_access_pointer(node->bit[0]) && !rcu_access_pointer(node->bit[1]) &&
+ (node->parent_bit_packed & 3) <= 1 && !rcu_access_pointer(parent->peer);
+ if (free_parent)
+ child = rcu_dereference_protected(parent->bit[!(node->parent_bit_packed & 1)],
+ lockdep_is_held(lock));
+ call_rcu(&node->rcu, node_free_rcu);
+ if (!free_parent)
+ return;
+ if (child)
+ child->parent_bit_packed = parent->parent_bit_packed;
+ *(struct allowedips_node **)(parent->parent_bit_packed & ~3UL) = child;
+ call_rcu(&parent->rcu, node_free_rcu);
+}
+
+static int remove(struct allowedips_node __rcu **trie, u8 bits, const u8 *key,
+ u8 cidr, struct wg_peer *peer, struct mutex *lock)
+{
+ struct allowedips_node *node;
+
+ if (unlikely(cidr > bits))
+ return -EINVAL;
+ if (!rcu_access_pointer(*trie) || !node_placement(*trie, key, cidr, bits, &node, lock) ||
+ peer != rcu_access_pointer(node->peer))
+ return 0;
+
+ remove_node(node, lock);
+ return 0;
+}
+
void wg_allowedips_init(struct allowedips *table)
{
table->root4 = table->root6 = NULL;
return add(&table->root6, 128, key, cidr, peer, lock);
}
+int wg_allowedips_remove_v4(struct allowedips *table, const struct in_addr *ip,
+ u8 cidr, struct wg_peer *peer, struct mutex *lock)
+{
+ /* Aligned so it can be passed to fls */
+ u8 key[4] __aligned(__alignof(u32));
+
+ ++table->seq;
+ swap_endian(key, (const u8 *)ip, 32);
+ return remove(&table->root4, 32, key, cidr, peer, lock);
+}
+
+int wg_allowedips_remove_v6(struct allowedips *table, const struct in6_addr *ip,
+ u8 cidr, struct wg_peer *peer, struct mutex *lock)
+{
+ /* Aligned so it can be passed to fls64 */
+ u8 key[16] __aligned(__alignof(u64));
+
+ ++table->seq;
+ swap_endian(key, (const u8 *)ip, 128);
+ return remove(&table->root6, 128, key, cidr, peer, lock);
+}
+
void wg_allowedips_remove_by_peer(struct allowedips *table,
struct wg_peer *peer, struct mutex *lock)
{
- struct allowedips_node *node, *child, **parent_bit, *parent, *tmp;
- bool free_parent;
+ struct allowedips_node *node, *tmp;
if (list_empty(&peer->allowedips_list))
return;
++table->seq;
- list_for_each_entry_safe(node, tmp, &peer->allowedips_list, peer_list) {
- list_del_init(&node->peer_list);
- RCU_INIT_POINTER(node->peer, NULL);
- if (node->bit[0] && node->bit[1])
- continue;
- child = rcu_dereference_protected(node->bit[!rcu_access_pointer(node->bit[0])],
- lockdep_is_held(lock));
- if (child)
- child->parent_bit_packed = node->parent_bit_packed;
- parent_bit = (struct allowedips_node **)(node->parent_bit_packed & ~3UL);
- *parent_bit = child;
- parent = (void *)parent_bit -
- offsetof(struct allowedips_node, bit[node->parent_bit_packed & 1]);
- free_parent = !rcu_access_pointer(node->bit[0]) &&
- !rcu_access_pointer(node->bit[1]) &&
- (node->parent_bit_packed & 3) <= 1 &&
- !rcu_access_pointer(parent->peer);
- if (free_parent)
- child = rcu_dereference_protected(
- parent->bit[!(node->parent_bit_packed & 1)],
- lockdep_is_held(lock));
- call_rcu(&node->rcu, node_free_rcu);
- if (!free_parent)
- continue;
- if (child)
- child->parent_bit_packed = parent->parent_bit_packed;
- *(struct allowedips_node **)(parent->parent_bit_packed & ~3UL) = child;
- call_rcu(&parent->rcu, node_free_rcu);
- }
+ list_for_each_entry_safe(node, tmp, &peer->allowedips_list, peer_list)
+ remove_node(node, lock);
}
int wg_allowedips_read_node(struct allowedips_node *node, u8 ip[16], u8 *cidr)
u8 cidr, struct wg_peer *peer, struct mutex *lock);
int wg_allowedips_insert_v6(struct allowedips *table, const struct in6_addr *ip,
u8 cidr, struct wg_peer *peer, struct mutex *lock);
+int wg_allowedips_remove_v4(struct allowedips *table, const struct in_addr *ip,
+ u8 cidr, struct wg_peer *peer, struct mutex *lock);
+int wg_allowedips_remove_v6(struct allowedips *table, const struct in6_addr *ip,
+ u8 cidr, struct wg_peer *peer, struct mutex *lock);
void wg_allowedips_remove_by_peer(struct allowedips *table,
struct wg_peer *peer, struct mutex *lock);
/* The ip input pointer should be __aligned(__alignof(u64))) */
static const struct nla_policy allowedip_policy[WGALLOWEDIP_A_MAX + 1] = {
[WGALLOWEDIP_A_FAMILY] = { .type = NLA_U16 },
[WGALLOWEDIP_A_IPADDR] = NLA_POLICY_MIN_LEN(sizeof(struct in_addr)),
- [WGALLOWEDIP_A_CIDR_MASK] = { .type = NLA_U8 }
+ [WGALLOWEDIP_A_CIDR_MASK] = { .type = NLA_U8 },
+ [WGALLOWEDIP_A_FLAGS] = NLA_POLICY_MASK(NLA_U32, __WGALLOWEDIP_F_ALL),
};
static struct wg_device *lookup_interface(struct nlattr **attrs,
static int set_allowedip(struct wg_peer *peer, struct nlattr **attrs)
{
int ret = -EINVAL;
+ u32 flags = 0;
u16 family;
u8 cidr;
return ret;
family = nla_get_u16(attrs[WGALLOWEDIP_A_FAMILY]);
cidr = nla_get_u8(attrs[WGALLOWEDIP_A_CIDR_MASK]);
+ if (attrs[WGALLOWEDIP_A_FLAGS])
+ flags = nla_get_u32(attrs[WGALLOWEDIP_A_FLAGS]);
if (family == AF_INET && cidr <= 32 &&
- nla_len(attrs[WGALLOWEDIP_A_IPADDR]) == sizeof(struct in_addr))
- ret = wg_allowedips_insert_v4(
- &peer->device->peer_allowedips,
- nla_data(attrs[WGALLOWEDIP_A_IPADDR]), cidr, peer,
- &peer->device->device_update_lock);
- else if (family == AF_INET6 && cidr <= 128 &&
- nla_len(attrs[WGALLOWEDIP_A_IPADDR]) == sizeof(struct in6_addr))
- ret = wg_allowedips_insert_v6(
- &peer->device->peer_allowedips,
- nla_data(attrs[WGALLOWEDIP_A_IPADDR]), cidr, peer,
- &peer->device->device_update_lock);
+ nla_len(attrs[WGALLOWEDIP_A_IPADDR]) == sizeof(struct in_addr)) {
+ if (flags & WGALLOWEDIP_F_REMOVE_ME)
+ ret = wg_allowedips_remove_v4(&peer->device->peer_allowedips,
+ nla_data(attrs[WGALLOWEDIP_A_IPADDR]), cidr,
+ peer, &peer->device->device_update_lock);
+ else
+ ret = wg_allowedips_insert_v4(&peer->device->peer_allowedips,
+ nla_data(attrs[WGALLOWEDIP_A_IPADDR]), cidr,
+ peer, &peer->device->device_update_lock);
+ } else if (family == AF_INET6 && cidr <= 128 &&
+ nla_len(attrs[WGALLOWEDIP_A_IPADDR]) == sizeof(struct in6_addr)) {
+ if (flags & WGALLOWEDIP_F_REMOVE_ME)
+ ret = wg_allowedips_remove_v6(&peer->device->peer_allowedips,
+ nla_data(attrs[WGALLOWEDIP_A_IPADDR]), cidr,
+ peer, &peer->device->device_update_lock);
+ else
+ ret = wg_allowedips_insert_v6(&peer->device->peer_allowedips,
+ nla_data(attrs[WGALLOWEDIP_A_IPADDR]), cidr,
+ peer, &peer->device->device_update_lock);
+ }
return ret;
}
wg_allowedips_insert_v##version(&t, ip##version(ipa, ipb, ipc, ipd), \
cidr, mem, &mutex)
+#define remove(version, mem, ipa, ipb, ipc, ipd, cidr) \
+ wg_allowedips_remove_v##version(&t, ip##version(ipa, ipb, ipc, ipd), \
+ cidr, mem, &mutex)
+
#define maybe_fail() do { \
++i; \
if (!_s) { \
test_negative(4, a, 192, 0, 0, 0);
test_negative(4, a, 255, 0, 0, 0);
+ insert(4, a, 1, 0, 0, 0, 32);
+ insert(4, a, 192, 0, 0, 0, 24);
+ insert(6, a, 0x24446801, 0x40e40800, 0xdeaebeef, 0xdefbeef, 128);
+ insert(6, a, 0x24446800, 0xf0e40800, 0xeeaebeef, 0, 98);
+ test(4, a, 1, 0, 0, 0);
+ test(4, a, 192, 0, 0, 1);
+ test(6, a, 0x24446801, 0x40e40800, 0xdeaebeef, 0xdefbeef);
+ test(6, a, 0x24446800, 0xf0e40800, 0xeeaebeef, 0x10101010);
+ /* Must be an exact match to remove */
+ remove(4, a, 192, 0, 0, 0, 32);
+ test(4, a, 192, 0, 0, 1);
+ /* NULL peer should have no effect and return 0 */
+ test_boolean(!remove(4, NULL, 192, 0, 0, 0, 24));
+ test(4, a, 192, 0, 0, 1);
+ /* different peer should have no effect and return 0 */
+ test_boolean(!remove(4, b, 192, 0, 0, 0, 24));
+ test(4, a, 192, 0, 0, 1);
+ /* invalid CIDR should have no effect and return -EINVAL */
+ test_boolean(remove(4, b, 192, 0, 0, 0, 33) == -EINVAL);
+ test(4, a, 192, 0, 0, 1);
+ remove(4, a, 192, 0, 0, 0, 24);
+ test_negative(4, a, 192, 0, 0, 1);
+ remove(4, a, 1, 0, 0, 0, 32);
+ test_negative(4, a, 1, 0, 0, 0);
+ /* Must be an exact match to remove */
+ remove(6, a, 0x24446801, 0x40e40800, 0xdeaebeef, 0xdefbeef, 96);
+ test(6, a, 0x24446801, 0x40e40800, 0xdeaebeef, 0xdefbeef);
+ /* NULL peer should have no effect and return 0 */
+ test_boolean(!remove(6, NULL, 0x24446801, 0x40e40800, 0xdeaebeef, 0xdefbeef, 128));
+ test(6, a, 0x24446801, 0x40e40800, 0xdeaebeef, 0xdefbeef);
+ /* different peer should have no effect and return 0 */
+ test_boolean(!remove(6, b, 0x24446801, 0x40e40800, 0xdeaebeef, 0xdefbeef, 128));
+ test(6, a, 0x24446801, 0x40e40800, 0xdeaebeef, 0xdefbeef);
+ /* invalid CIDR should have no effect and return -EINVAL */
+ test_boolean(remove(6, a, 0x24446801, 0x40e40800, 0xdeaebeef, 0xdefbeef, 129) == -EINVAL);
+ test(6, a, 0x24446801, 0x40e40800, 0xdeaebeef, 0xdefbeef);
+ remove(6, a, 0x24446801, 0x40e40800, 0xdeaebeef, 0xdefbeef, 128);
+ test_negative(6, a, 0x24446801, 0x40e40800, 0xdeaebeef, 0xdefbeef);
+ /* Must match the peer to remove */
+ remove(6, b, 0x24446800, 0xf0e40800, 0xeeaebeef, 0, 98);
+ test(6, a, 0x24446800, 0xf0e40800, 0xeeaebeef, 0x10101010);
+ remove(6, a, 0x24446800, 0xf0e40800, 0xeeaebeef, 0, 98);
+ test_negative(6, a, 0x24446800, 0xf0e40800, 0xeeaebeef, 0x10101010);
+
wg_allowedips_free(&t, &mutex);
wg_allowedips_init(&t);
insert(4, a, 192, 168, 0, 0, 16);
* WGALLOWEDIP_A_FAMILY: NLA_U16
* WGALLOWEDIP_A_IPADDR: struct in_addr or struct in6_addr
* WGALLOWEDIP_A_CIDR_MASK: NLA_U8
+ * WGALLOWEDIP_A_FLAGS: NLA_U32, WGALLOWEDIP_F_REMOVE_ME if
+ * the specified IP should be removed;
+ * otherwise, this IP will be added if
+ * it is not already present.
* 0: NLA_NESTED
* ...
* 0: NLA_NESTED
};
#define WGPEER_A_MAX (__WGPEER_A_LAST - 1)
+enum wgallowedip_flag {
+ WGALLOWEDIP_F_REMOVE_ME = 1U << 0,
+ __WGALLOWEDIP_F_ALL = WGALLOWEDIP_F_REMOVE_ME
+};
enum wgallowedip_attribute {
WGALLOWEDIP_A_UNSPEC,
WGALLOWEDIP_A_FAMILY,
WGALLOWEDIP_A_IPADDR,
WGALLOWEDIP_A_CIDR_MASK,
+ WGALLOWEDIP_A_FLAGS,
__WGALLOWEDIP_A_LAST
};
#define WGALLOWEDIP_A_MAX (__WGALLOWEDIP_A_LAST - 1)
} < <(n0 wg show wg0 allowed-ips)
ip0 link del wg0
+allowedips=( )
+for i in {1..197}; do
+ allowedips+=( 192.168.0.$i )
+ allowedips+=( abcd::$i )
+done
+saved_ifs="$IFS"
+IFS=,
+allowedips="${allowedips[*]}"
+IFS="$saved_ifs"
+ip0 link add wg0 type wireguard
+n0 wg set wg0 peer "$pub1" allowed-ips "$allowedips"
+n0 wg set wg0 peer "$pub1" allowed-ips -192.168.0.1/32,-192.168.0.20/32,-192.168.0.100/32,-abcd::1/128,-abcd::20/128,-abcd::100/128
+{
+ read -r pub allowedips
+ [[ $pub == "$pub1" ]]
+ i=0
+ for ip in $allowedips; do
+ [[ $ip != "192.168.0.1" ]]
+ [[ $ip != "192.168.0.20" ]]
+ [[ $ip != "192.168.0.100" ]]
+ [[ $ip != "abcd::1" ]]
+ [[ $ip != "abcd::20" ]]
+ [[ $ip != "abcd::100" ]]
+ ((++i))
+ done
+ ((i == 388))
+} < <(n0 wg show wg0 allowed-ips)
+ip0 link del wg0
+
! n0 wg show doesnotexist || false
ip0 link add wg0 type wireguard
$(eval $(call tar_download,IPTABLES,iptables,1.8.7,.tar.bz2,https://www.netfilter.org/projects/iptables/files/,c109c96bb04998cd44156622d36f8e04b140701ec60531a10668cfdff5e8d8f0))
$(eval $(call tar_download,NMAP,nmap,7.92,.tgz,https://nmap.org/dist/,064183ea642dc4c12b1ab3b5358ce1cef7d2e7e11ffa2849f16d339f5b717117))
$(eval $(call tar_download,IPUTILS,iputils,s20190709,.tar.gz,https://github.com/iputils/iputils/archive/s20190709.tar.gz/#,a15720dd741d7538dd2645f9f516d193636ae4300ff7dbc8bfca757bf166490a))
-$(eval $(call tar_download,WIREGUARD_TOOLS,wireguard-tools,1.0.20210914,.tar.xz,https://git.zx2c4.com/wireguard-tools/snapshot/,97ff31489217bb265b7ae850d3d0f335ab07d2652ba1feec88b734bc96bd05ac))
+$(eval $(call tar_download,WIREGUARD_TOOLS,wireguard-tools,1.0.20250521,.tar.xz,https://git.zx2c4.com/wireguard-tools/snapshot/,b6f2628b85b1b23cc06517ec9c74f82d52c4cdbd020f3dd2f00c972a1782950e))
export CFLAGS := -O3 -pipe
ifeq ($(HOST_ARCH),$(ARCH))
projects / linux-block.git / commitdiff